Hadith 4:402

Narrated Abu Huraira:

Abu Bakr, on the day of Nahr (i.e. slaughtering of animals for
sacrifice), sent me in the company of others to make this
announcement: "After this year, no pagan will be allowed to perform
the Hajj, and none will be allowed to perform the Tawaf of the Ka'ba
undressed." And the day of Al-Hajj-ul-Akbar is the day of Nahr, and it
called Al-Akbar because the people call the 'Umra Al-Hajj-ul-Asghar
(i.e. the minor Hajj). Abu Bakr threw back the pagans' covenant that
year, and therefore, no pagan performed the Hajj in the year of
Hajj-ul-Wada' of the Prophets.